The tech tree structure is bugging me.
Theres a bit of a pattern I'm noticing in my games that I'm not satisfied with. Because techs get more powerful as you progress through the tree, I'm finding that spreading my research out is punishing me more than helping me. I very often find myself advanced in one tree and completely neglecting the others. There are some very crucial techs midway up these trees that you kinda need to get first before you think about other trees. One that comes to mind is the training of groups of soldiers.
I can't seem to use my tech research to shape the character of my faction. With 5 different trees it would seem that I have many options, but I don't really. I'd like to see some more cross dependancy between the different trees, so that there are many paths of progression rather than just climbing one tree. I would say that the higher techs need to be more expensive in order to force people to spread out, but then the civics tree becomes the tree you need to focus on first until you get greater research capacity. Maybe the techs should be more powerful at the bottom, so that specialization happens at a later point in the game, and is more of a refinment of your capabilities than an all or nothing 'one trick pony' kinda thing.
I think that the way the system is structured creates problems that are difficult to solve. I kinda wish that if the trees can't be brought together, then maybe they should be completely separate, in that you use entirely different resources to progress in each one, so that instead of this severe trade-off of your precious research points, your kingdom can walk and chew gum at the same time, depending on what resources are available.